Place a large pot over high heat and bring to a boil for the pasta. Once boiling, add some salt and drop in the pasta. Cook to al dente, according to the package directions.
While the water is coming up to a boil, in a medium size skillet over medium-high heat, heat two turns of the pan of EVOO. Add the pancetta and brown, about 3 minutes.
Add the garlic and crushed red pepper flakes and cook for 1-2 minutes. Add the red onion and cook for another 5 minutes. Add the tomatoes, some salt and lots of freshly ground black pepper. Cover and cook about 7-8 minutes, or until the tomatoes burst.
Add the al dente spaghetti or linguine to the skillet along with the basil, parsley and Parmigiano Reggiano cheese. Just before serving, top with arugula.